Moulded pulp packing and method for producing same



y 1956 E. L. HARTMANN 3,

MOULDED PULP PACKING AND METHOD FOR PRODUCING SAME Filed Jan. 17, 1964 3Sheets-Sheet 1 Fig. 1

INVENTOR ATTORNEY July 5, 1966 E. L. HARTMANN MOULDED PULP PACKING ANDMETHOD FOR PRODUCING SAME Filed Jan. 1'7, 1954 2 Sheets-Sheet 2 u u Q aF M M as JMHWMF/ WW6 2 2 #7 u 4 M INVENTOR /:6 g 1 ATTORNEY UnitedStates Patent 0 M 4 Claims. ((Il. 229-25 The invention relates to amoulded pulp packing, especially a packing of this kind adapted tocontain a number of eggs or other fragile or delicate objects,consisting of two parts, hinged together and constituting a lower partand an upper part, which parts when folded together enclose the objects,and of a locking flap hinged to the lower part. When this flap is in aninwardly swung position in which it is situated internally in the upperpart a projection on the flap engages a corresponding aperture in thelateral wall of the upper part and locks the two parts together.

For technical reasons packings of this kind are manufactured in open orunfolded condition. The suction mould employed in the manufacturingprocess must be so arranged that the blank absorbed on the mould can bereleased from the latter in the same manner as known in connection withcast iron. In practice, the requisite inclination of all surfaces risingfrom the base of the mould is so adapted that the packings formed, afterdrying, can be nested, i.e. piled closely together. This property iseasily obtained as far as the lower part and the upper part of thepacking are concerned, but difficulties are encountered with the lockingflap, because the locking projection on this flap, which duringproduction is usually situated at the level of the base of the mouldwhere there is unintentionally imparted an increased thickness ofmaterial, and because it has on the outer side, an inclination smallerthan that of the other inclining surfaces of the packing. When suchpackings are nested, the locking flaps of packings following one anotherwill therefore form a fan, which ultimately prevents further piling.

When packings are produced by machines from which the blanks in moistand therefore plastic condition are deposited on the plane surface of aconveyor, by which means they are passed through a drying kiln, the saidsurface must constitute a support for the blanks so as to preserve theshape imparted to them by the suction moulds. In order to be certainthat the smoother surface is produced on the outer side of the packingand also in order to provide the most effective support, the blanks areso deposited on the conveyor that the lower side of the lower part andthe upper side of the upper part will rest on the conveyor. In that casethe locking flap which, in known packings, is on a level with theadjacent surfaces of the lower part and the upper part will have nosupport, so that it will be subject to buckling or to permanentdeformation during the passage of the blank through the kiln, which maynecessitate a subsequent pressing of the whole blank.

An object of the present invention is to provide such a locking flapconstruction that it does not adversely influence the nesting of thepackings.

Another object of the invention is to provide a fiap structurepreventing it from being deformed during the passage of the blanksthrough the drying kiln.

A further object of the invention is to provide a locking flap so shapedthat it is easily produced on suction moulds and has a lockingprojection which furthermore ensures a safe locking.

A still further object of the invention is to provide a method forproducing moulded pulp packings having the above properties.

3,259,294 Patented July 5, 1966 According to the invention, the packingis produced with a locking flap occupying an outward oblique positionand having a free edge portion lying in the plane of the bottom of thelower part.

When this packing blank is deposited on the conveyor the free edgeportion of the flap will come to rest on a plane surface in the same wayas the lower part and the upper part, and therefore, the flap will bewell supported during the drying of the blank.

It is expedient that the free edge portion of the locking flap bereinforced by means of an outwardly protruding ledge, which forms suchan angle with the flap proper when in a downwardly oblique position thatthe ledge is located in the plane of the bottom of the lower part.

By this means a particularly good support for the flap is provided andalso a bracing against deformation.

It is preferred that the flap proper and the ledge adjoin along a wavedcurve in the plane of the ledge in order to reduce the possibility of aswinging movement of the ledge in relation to the flap proper duringdrying.

According to the invention the flap is provided with at least oneprojection shaped like a downwardly open nose, of uniform thickness andwith a recess or opening therebelow, the width of which preferablyincreases towards the hinge edge of the flap.

Other characteristic features of the invention and the advantagesderived therefrom will appear from the following description, referencebeing had to the accompanying drawings.

The drawings illustrate an embodiment of the packing designed to containten eggs, placed in two rows. The lower part of the packing has a shapewhich is specially designed for this purpose. It is emphasized, however,that the invention is not dependent on this design of the lower part,since it can be applied to other packings which are constructed of twoparts hinged together, irrespective of their shape. Still, the inventionis most suitable for packings in which the upper part is shaped as atrough with plane base and oblique lateral wall inclining at the slipnecessary for the moulding of the blanks and the nesting of thepackings.

In the drawings:

FIG. 1 is a view of the packing fro-m above, in unfolded condition;

FIG. 2 is a cross sectional view taken on the line II-II in FIG. 1showing the packing in closed condition and on an increased scale; and

FIG. 3 is a broken front view of the packing in closed condition showingthe locking arrangement.

The packing according to the invention is produced by precipitatingfibre pulp by suction on a mould having a reticulated or perforatedsurface, in such a manner that substantially the same thickness ofmaterial is applied to all portions of the packing.

The packing, as shown in the drawings, comprises a lower part 10, anupper part 12 and a locking flap 14. The upper part 12 and the flap 14are integral with the lower part 10 and hinged to its opposite sides bymeans of fold lines 16 and 18, which act as hinges. A number ofdepressions 20 are provided in the lower part 10, each of which isdesigned to receive one end of an egg. The design of the lower part isotherwise determined by the need for providing the requisite strengthand rigidity, which, however, is not relevant to the present invention.

The upper part 12 of the packing is provided with an oblique lateralwall 22 having an undulating outline arranged to fit around the outersurfaces of the upper portions of the eggs as shown in FIG. 1, and aflat top wall 24. The upper and lower parts are provided with edgeflanges 26 which abut against one another when the packing is closed,except along the front, as shown in FIGS.

2 and 3, where the flange 26 along the front of the upper part 12 abutsagainst a flange 27 of the flap 14.

The flap 14 comprises an oblique wall 28 extending upwardly from itsflange 2'7 and having the same undulating outline as the part of thelateral wall 22 of the upper part 12 overlying the flap 14, and a ledge30 forming an angle with the wall 28, equal to the angle between the top24 and the oblique lateral wall 22 of the upper part 12, as shown insection in FIG. 2.

For the purpose of locking the said packing in closed condition thereare provided on the locking flap 14, as shown in FIGS. 2 and 3, twospaced projections 32 cooperating respectively with rectangularly-shapedapertures 34 in the adjacent lateral wall 22 of the upper part 12. Thelocking projections 32 are located at the free edge portion of the flap14, where it adjoins the ledge 30, as shown in FIG. 2 of the drawings.

Each projection 32 is shaped like a nose or a lip, open at the bottom,having an inclining front wall 36 (FIG. 2) and two parallel lateralwalls 38. A U-shaped reinforcement in the form of an encircling externalhead 40 is provided along the lower outside edge portions of theinclining wall 36 and the side walls 33.

A recess or opening 42 is provided or left in the oblique wall 28 of thelocking flap 14 below each projection 32 for facilitating the release ofthe packing blank from the mould. The width of the openings 42 increasesfrom the bottom of the beads 40 toward the fold line 18 or flange 27 asshown in dotted lines in FIG. 3. The openings 42 also provide weakenedareas in the locking flap which facilitate the movement of theprojections 32 inwardly to release the upper portion of the packing. Theshape and location of the openings 42 facilitate removal of the packingsfrom the mould, since the openings are left in the packing by beingformed around projecting portions of the mould which have portionsextending along the lower faces of the beads 40. At the end of amoulding operation, the projecting part of the mould extends through theopening 42. The mould, of course, includes projecting portions overwhich the locking projections 32 are formed.

When the packing is to be closed, the locking flap 14 is swung about thefold line 18 from the dotted line position shown in FIG. 2, upwardly andinwardly into the position shown in full lines, whereupon the upper part12 is swung about the fold line 16 upwardly and inwardly, until it comesto rest against the lower part 10 and the flange 27. During the lastphase of this movement the front of the lateral wall 22 of the upperpart under the openings 34 will be forced outwardly and thereupon springback, the projections 32 simultaneously engaging the respective openings34. An internal reinforcing head 44 is provided at the lower edge ofeach opening 34 over which the projections 32 slide. In locked conditionthe ledge 30 of the locking flap 14 extends along the lower side of theplane top 24 of the upper part, as shown in FIG. 2.

The shape of the projections 32 herein described as a downwardly opennose or lip makes it possible to make the thickness of the material ofthe projections the same as that of the other parts of the packing, andwhen the packing is produced with the locking flap 14 in the positionshown in dotted lines in FIG. 2, the flap forms no obstacle to thenesting of the packings.

Having now fully described my invention I claim as new and desire tosecure by Letters Patent:

1. In a moulded pulp packing including a hollow lower part and an uppercup-shaped part having an oblique lateral wall so as to be readilyreleasable from the mould in which the packing is formed, said partsbeing hinged together with a lower edge of the upper part hinged to anupper edge of the lower part, and a locking flap hinged by its loweredge to the upper edge of the lower part opposite the position of thehinge between the upper and lower parts, said locking flap extendingupwardly within and along the oblique wall of the upper part when it isin closed position and including a locking projection cooperating withan opening in said oblique wall of the upper part to lock the packing inclosed condition when the upper part is brought over the lower part andthe locking flap, and in which the locking projection is located at theupper portion of the locking flap, said locking flap being provided witha recess therein extending downwardly from the lower edge of the lockingprojection, and an outwardly-projecting reinforcing bead extendingaround the lower edge of the locking projection.

2. A moulded pulp packing as claimed in claim 1, in which the lockingprojection includes front and side walls and opens at the bottom intosaid recess, and in which said bead extends from the face of the lockingflap on one side of the locking projection to the face of the lockingflap on the other side of the projection.

3. In a moulded pulp packing including a hollow lower part and an uppercup-shaped part having an oblique lateral wall so as to be readilyreleasable from the mould in which the packing is formed, said partsbeing hinged together with a lower edge of the upper part hinged to anupper edge of the lower part, and a locking flap hinged by its loweredge to the upper edge of the lower part opposite the position of thehinge between the upper and lower parts, said locking flap extendingupwardly within and along the oblique wall of the upper part when it isin closed position and including a locking projection cooperating withan opening in said oblique wall of the upper part to lock the packing inclosed condition when the upper part is brought over the lower part andthe locking flap, and in which the locking projection is shaped like adownwardly open nose and is located at the upper portion of the lockingflap, said locking flap being provided with a recess therein extendingdownwardly from the lower edge of the locking projection.

4. A moulded pulp packing as claimed in claim 3, in which the lockingprojection includes front and side walls and opens at the bottom intosaid recess, and an external reinforcing bead encircling the lower freeedge of the locking projection, said bead extending from the face of thelocking flap on one side of the locking projection to the face of thelocking flap on the other side of the projection.

References Cited by the Examiner UNITED STATES PATENTS 2,446,264 8/1948Cox 2292.5 2,600,130 6/1952 Schilling 2292.5 2,752,084 6/ 1956 Shepard2292.5 2,843,304 7/1958 Reifers 22929 3,028,065 4/1962 Reifers 2292.53,034,693 5/1962 Cox 2292.5 3,144,973 8/ 1964 Heintzelman 22929 5 JOSEPHR. LECLAIR, Primary Examiner.

J. F. MCNULTY, D. F. NORTON, Assistant Examiners.

3. IN A MOULDED PULP PACKING INCLUDING A HOLLOW LOWER PART AND AN UPPERCUP-SHAPED PART HAVING AN OBLIQUE LATERAL WALL SO AS TO BE READILYRELEASABLE FROM THE MOULD IN WHICH THE PACKING IS FORMED, SAID PARTSBEING HINGED TOGETHER WITH A LOWER EDGE OF THE UPPER PART HINGED TO ANUPPER EDGE OF THE LOWER PART, AND A LOCKING FLAP HINGED BY ITS LOWEREDGE TO THE UPPER EDGE OF THE LOWER PART OPPOSITE THE POSITION OF THEHINGE BETWEEN THE UPPER AND LOWER PARTS, SAID LOCKING FLAP EXTENDINGUPWARDLY WITHIN AND ALONG THE OBLIQUE WALL OF THE UPPER PART WHEN IT ISIN CLOSED POSITION AND INCLUDING A LOCKING PROJECTION COOPERATING WITHAN OPENING IN SAID OBLIQUE WALL OF THE